Elevator control system



July 31, 1934. M. BARUCH 1,968,551

ELEVATOR CONTROL SYS TEM Filed Sept. 30, 1930 gwwnto'c Patented July 31, 1934 1 Fri EL vAroa, CONTRO SYSTEM Milton Baruch, Los'Angeles}.0alif.; assignonlzby mesne assignments, to .iWestinghouse Electric Elevator Company, a corporation of Illinois a pirants September so; 1930,;sria1iv 4855353 4 Claims. (01. 1875-29) My invention relates to motor control systems, and hasparticular reference to a system of control for an electric elevator. a.

Modern high speed elevators are usually operated at such high speeds that it is essential that the elevator shall be accurately decelerated in order to make accurate landings at the various floor levels which they serve. Moreover, the high speeds at which modern elevators operate make it extremely difficult for attendants on the cars to make the necessary stops in response to signals registered by waiting passengers at the various floors, and it is, therefore-desirable to have the stopping of the car initiated automatically rather than to depend upon the action of the operator.

, On the other hand, it is not desirable to entirely remove the stopping control of the operating car from thehands of the operatoror att ndant since it is frequentlynecessary for him to stop the car independent of signals, for example, a person on the car may fail to announce the floor atwhich he desires to leave the car until after the car has passed the desired stopping point. It is, there fore, necessary that the operator shall have underhis control means for stopping and: reversing the car to allow that passenger to be taken'back to the place desired. 4 A

It is an object of my invention, therefore, to provide an elevator control system in which the car is at all times under the immediate control of the attendant on the car, but which may be stopped automatically in response to the pas-1 sengers signals without the necessity of any man-. ual manipulation of the control by the attendant on the car.

It is another object of my inventicnto provide an elevator control system in which either the attendant on the car or the passengersldesiring to board or leave the car may cause the car to auto inat-ically stop at the desired floors; 1

Another object of my invention isdto provide an elevator control system of the character'set forth'in the preceding'paragraph in which, 'irre spe'ctive of whether the'car is tobe stopped by the attendant or by the passengers signals, the'car will always be automatically decelerated and stopped at the floor landing. i

, Another object of invention is "to provid a control system of the character described in which the usual signal'systeins no N employed with,

My in -zentionavill be described with reference to the accompanying drawing, in which the sole elevator is to operate. j, Since it is essential that th elevator car shall.

figure is-a diagrammatic view of an elevator, its motorcontrol system, andv the usual signalling system employed with attendant-controlled ele vators arranged in accordance with my invention. Referring to the drawing, .1 have illustrated therein an elevator car C of the usual construction, suspended in the well-known manner upon a cable Cd whichpa'sses over a hoisting drum D and is counter-balanced by a suitable counterweight, CwQ The motive power for. the elevator maybe of any existing character, though I prefer to ernploy the variable voltage system, which comprises an elevatormotorEM having an armature .EM directly connected to the hoisting drunrD.

' The field winding'jE. M F; of the elevator motor EM is arranged to becontinuously energize'df with constant current fromv any suitable source, 'such as is represented by line conductors L,l-and L 2. 3

The armature EM of the elevator EM is connected inloop circuit with an armature G of a generator G. The generator G is provided with a series field winding GSFconne'cted in the loop circuit'to provide the necessary compensation for variations in load upon the elevatorcar. j

-,The generator G is also providedwijth a separately excited field winding G F arranged tobe supplied with current from the sources of supply. L"1 and L-- 2, to therebyicontrol the direction and speed of operation of the. elevator motor EM. Thefield winding GE is illustrated as being connectedfor, energization through the operation of an up-direction switch 1 and a down-direction switch, 2, which, when operated will re spectively connect the field winding GE to the source of supply with current flowing one direction or the other, respectively, In circuit with the field win'ding GlF, I have illustrated an auxiliary resis'tor'R which may beexcluded from'the circuit or included therein by means of a suitable speed relay3. The elevator car is provided with a car'switch Cs under the control. of an attendant thereon to select the direction of operation of the elevator and alsotoicontrol the speed atwhich' the be accurately decelerated in order to makeastop at-theexact-floor levels, I have illustrated what is commonly known in the art as a landing system, which may be of any well-knownconstruction but. which I have illustrated as comprising a landing device LD which includes a pair of drums .or cams sc andDC, 'lfhese drums are mounted upon a suitable shaft S arranged to be driven in synchronism with the movements of the elevator car, as by connecting the same through suitable gearing GR to a drum (1 over which passes a drum cable do one end of which is connected. at 10 to the elevator car C. and the other end of which is connected to a suitable counterweight cw. By properly proportioning the gearing GR, the drum SC may be caused to make a complete revolution during one trip of the elevator car from its lower terminal to its upper terminal, and correspondingly the deceleration or slowing-down drum DC will likewise make a complete revolution during a complete trip of the elevator car only from one end of its shaft to the other.

I have illustrated the drums SC and DC as being in the form of cams having variously extending levels thereon to engage and operate associated cam-actuated switches SCS and DCS, respectively. The deceleration cam DC is provided with a lower lever or a depression therein 11 for each of the floors, which is to be served by the elevator car, for example, the depression 12 is associated with the first floor; depression 13 with the second, and so forth.

It will be observed that the length of the depressions 11, 12 and 13, etc., are of relatively great length, being of such length as to correspond to the required slow-down distance for the car as it approaches the corresponding floor either in the up or down direction. That is, duringthe passage ofthe car from one floor to the next floor, the switch DCS will ride upon the outermost face of the cam until the car approaches that distance from the next floor at which deceleration should be initiated. The cam then drops into the depression and, as will hereinafter be described, the car will be brought to rest with the switch DCS in a position approximately central with respect to the depression in the cam DC.

Likewise, the stopping drum or stopping cam SC is provided with a set of depressions 15, 16, 17 and 18, each of which corresponds to one of the floors to be served by the car.

It will be noted that the depressions 15, 16, 17 and 18 in the cam SC are of relatively short length; that is, when the car is exactly at a floor level the corresponding depression will be aligned with the switch SCS.

I have illustrated the usual signaling system now in common use in connection with attendantcontrolled elevators. This signaling system comprises an up-push button and a down-push button for each of the floors served by the car, these buttons being designated as BUB for the up-direction for the third floor, and 3DB for the downdirection for the third floor; 2UB for the up-direction for the second floor, and 2DB for the down-direction for the second floor. 7

It will be understood that the car will be automatically stopped at the terminal floors independent of any signals and therefore no buttons are illustrated for the first and fourth floors, it being assumed that the first and fourth floors are terminals of the elevator.

Each of the push buttons has associated therewith a signaling registering relay, that for the third floor up-button being designated by the reference character 3UR; that for the third floor down-button being designated by the reference character 3DR, etc.

Also, each of the floor buttons has associat d therewith a cancellation or reset relay designated by the reference characters 3UC, 3DC, etc.

The fioor buttons have associated therewith a suitable floor selector ES which comprises a suitable base, not shown, upon which are mounted a plurality of sets of segmental contacts arranged in lines or groups, over which passes a movable arm MA carrying a plurality of brushes for engagement with the groups of segmental contacts.

The construction of the floor selector is that ordinarily employed in elevator signaling systems and it is not deemed necessary to recite the construction in detail.

On the elevator car C I have illustrated the usual flash signal lamp FL which is to be actuated by the signal buttons BUB and 3DB, etc., in the manner well-known in the elevator art.

Connected in parallel relation to the flash signal lamp FL, I have illustrated a stopping relay Sr which is arranged to be energized whenever the flash signal lamp is lighted to thereby cause the elevator car to be automatically stopped at the floor in response to the signal in the event that the attendant should fail to respond to the signa My invention will best be understood with reference to assumed operation. Assuming the elevator car to be standing at the first floor preparatory to traveling upwardly, the attendant on the car C may operate the car switch Cs in a counterclockwise direction. 7

Movement of the car-switch Cs will complete a circuit for energizing the up-direction switch which will thereby cause the car to start upwardly. The circuit for the Lip-direction switch 1 extends from line conductor Ll through conductor 20, the usual door and gate safety interlocking switches indicated by legend, conductor 21, the normally closed contact members of relay Sr, conductor 22, contact members 23, 24 and 25 on car-switch Cs, conductor 26, coil of up-direction switch 1, conductors 2'7 and 28 to line conductors L2. The up-direction switch 1, when energized, closes its contact members I) and c to thereby complete a circuit for the separately excited field winding GF on the generator G, which circuit extends from line conductor Ll, through conductor 270, 280 and 29, contact members b on the up-direction switch 1, conductor 30, field winding GF, conductors 31 and 32; contact members c on up-direction switch 1, conductors 34 and 35, resistor R to line conductor L-2. Hence the car will start upwardly at a speed determined by the amount of effective resistance in the resistor R.

If it is desired that the car should travel at its normal high speed, the attendant on the car may move the car-switch Cs to a further position in a counter-clockwise direction to complete a circuit for energizing speed relay 3. This circuit extends from line conductor Ll through conductors 20 and 21 and 22, contact members 23, 24 and 36 on car-switch Cs, conductor 37, the coil of speed relay 3 and conductor 38 to line conductor L2. The speed relay 3, when energized, closes its contact members to shunt resistor R from the circuit of the generator field winding, thus allowing full line voltage to be supplied to the field winding GF and the car will thereafter travel at high speed.

While I have illustrated only one auxiliary relay 3 to produce one step of speed, it will be understood that additional steps of speed may be employed by providing additional speed relays for shunting a plurality of sections of resistor R in steps.

The car, therefore, proceeds upwardly in the shaft at a high speed as long as the attendant holds the car-switch Cs in the position in which it has been moved. If the car-switch should be centered or returned to its off position, at any time, the car will come to a stop.

I prefer that the car shall always come to a stop at a level with one of the floors. Hence, assuming that as the car approached the third floor, the attendant moved the car-switch Cs to its oil position, the car would not immediately come to a stop since a second circuit for energizing the up-direction switch 1 is completed through cam-actuated switch SCS. This circuit extends from line conductor L-l through conductor 39, contact members of cam-actuated switch SCS, conductors 40 and 41, contact members a on updirection switch 1 (now closed since the up-direction switch was energized), conductor 42, and thence through the coil of the up-direction switch 1 to line conductor L2, as previously traced. Also, an auxiliary circuit will be completed through the decelerating cam-actuated switch DCS for speed relay 3, thus holding this relay in actuated position, this circuit extending from line conductor Ll, through conductor 39, contact members of switch DCS, conductor 43, the coil of speed relay 3 and conductor 38 to line conductor L-2.

As the car approaches the proper slow-down distance at which deceleration from normal high speed must be initiated in order to bring the car to an accurate stop at the floor landing, the deceleration cam-actuated switch DCS will drop off of the high point of cam DC and will thereby open its contacts, thus breaking the circuit for speed relay 3, allowing this relay to reinsert the resistor R in the generator field winding circuit to thereby slow-down the car.

As the car, now traveling at slow speed, approaches the exact floor level, cam SC will move to such position as to allow the cam-actuated switch SCS, associated therewith, to fall into the third floor depression on that cam and switch 808 will thereby be opened to deenergize the updirection switch and bring the car to rest accurately at the floor level.

The attendant may then open the door at the third floor, designated by the reference character 3FTD, and during the entire time the door is opened the door and gate interlocking switches will be open to prevent restarting of the car until after the door is reclosed.

The car may also be stopped in response to the registration of a signal by a person waiting to board the car. Assuming that the car is again at the first floor prepared to travel upwardly, and a person at the second floor desires to travel upwardly, and presses the button 2-UB, the operation of the button 2UB registers the signal by actuating the signal registering relay ZUR, the circuit of which extends from line conductor L-l through conductor 44, contact members or button 2UB, conductor 45, of coil of relay ZUR, normally closed contact members of cancellation relay ZUC and conductors 47 and 48 to line conductor L--2. The energization of relay ZUR closes its contact member a to complete a selfholding circuit therefor so that button ZUB may be released after momentary operation and also closes its contact member b to supply current to contact segments 49 on floor selector PS.

The self-holding circuit for relay ZUR extends from line conductor L1 through conductor 50, contact member a on relay ZUR and conductor 51 to the coil of relay ZUR, closes the circuit as previously traced to line conductor L---2. The

circuit for energizing contact segment 49 extends from line conductor L-l through conductors and '52, contact member 22 on relay .ZUR, conductor 53 to a junction point 54, thence by way of branch conductor to contact segment 49..

It is assumed that elevator car C,'which is illustrated, is only one of a bank of elevator cars and for this reason conductor 53 extends beyond the junction point 54 to connect with corresponding segments on the floor selectors for each of the remaining cars in the bank.

As the elevator car C leaves the first floor, the floor selector FS will have its movable arm MA in a position to engage contact segment 49 to thus bridge between contact segment 49 and a continuous contact strip 55 thus completing a circuit for operating the flash signal lamp FL and stop relay SR.

The circuit for the flash lamp FL extends over contact segment 49 through brush 56 on floor selector FS, continuous contact 55, conductors 57 and 58, flash signal lamp FL, conductor 59 to normally closed contacts of a by-pass push button BP and conductor 60 to line conductor L2, while a branch circuit extends from conductor 57 through'the coil of stop relay SR, conductor 61 to conductor 59 and thence through the by-pass, push button to line conductor L-2. Hence the flash lamp FL will be lighted to indicate in the car that a stop is to be made at the second I'ioor, while, at the same time, stop relay SR'will be actuated to open the feed circuit to the carswitch Cs to form exactly the same function as though the car-switch Cs had been returned to its off or central position.

The opening of the normally closed contact members of relay SR upon the energization of its coil, breaks the circuit through conductors 21 and 22 which normally supply current to the car-switch Cs. Hence as the car approaches the second floor, the sequential opening of decelerating cam switch DCS and stop cam switch 503 will bring the car to a stop at the second floor level.

It will be observed that if the car-switch is not centered and stop relay SR is not ener iz the opening of the landing device switches DCS and SCS will have no effect upon the operation of the elevator car, since -these switches control only parallel circuits to the rip-direction switch 1 and speed relay-3 in parallel relation to the circuits which are maintained through the carswitch Cs.

Assuming that the car has stopped at'the second floor, the attendant opens the second floor door ZFD to allow the passenger waiting thereat to board the car, the opening of the sec-. ond floor door ZFD breaks the interlocking switches to prevent starting of the car by the attendant until the door is closed again and, in

addition, the opening of the second floor door 2FDoperates a door switch 62 to complete cir-. cuit for cancelling or restoring the signals which has been registered by the button ZUB. This manner of resetting the signals is well-known in the elevator signal art and is illustrated herein by having the door switch 62 complete a circuit for the cancellation relay 2UC, which circuitextends from line conductor L-l through conductor 63, the coil of the second floor cancellation relay. ZUC, conductor 64 to a junction .65, whence'one branch extends byway of conductor 66 to cancellation contact segment 67 on floor selector FS. When the car is standing at the second floor level a brush 68 and the movable arm MA of the floor selector will bridge contact segment 67 with a continuous contact member 69, thus supplying current through conductor 70 contact members '71 on the door switch 62 and conductors 72 and 48 to line conductor "L2. The energization of the cancellation relay ZUC opens its normally closed contact members which were located in the self-holding circuit for signal registering relay ZUR and the signal registering relay 2UR is thereby restored to normal open circuit position.

It is assumed that as the car came to rest at the second floor level, the operator centered the car-switch Cs, though it is not essential that he should doso instantly upon the stopping of the car, since the stopping relay SR will remain energized until the cancellation relay ZUC is actuated by the opening of the door. Hence the stopp ng of the car at the second floor level is insured and it is impossible for the attendant to restart the car Without first opening the door to admit the passenger; even though the attendant should attempt to do so by manipulation of the car-switch Cs.

However, it is sometimes necessary that the attendant should pass signals, for example, when the car is too crowded to admit more passengers, and it is for this reason that the by-pass button BP, which is usually provided for in signaling systems, is arranged to be operated by the attendant under such conditions. If the by-pass button 3? is actuated, the signal relay SR will not be energized or if energized its circuit will be broken to again restore to the attendant on the car the control of the car.

Conductor 64 extends to all of the cars in the bank in a manner similar to that described for conductor 54 so that by connecting conductor 64 to corresponding cancellation contact members on the floor selectors associated with the remaining cars in the bank, it will be understood that the first car to arrive at a signaled floor will stop thereat and will restore the signals to their normal deenergized condition.

It will be observed, therefore, that I have provided an elevator control system which may be adapted to any elevator provided with a landing system which permits of automatic deceleration of the car to make accurate landings at the floor and the system which I have devised may be connected so that the passengers signals may automatically initiate the stopping operation of the car by the mere addition of a stop relay, the coil of which is in parallel relation with the usual flash signal lamp of such signaling systems.

It will also be observed that I have illustrated on the elevator car C a plurality of push buttons C2, C3, one of which is associated with the second floor and one with the third floor, so that persons on the car may register the floors at Which they desire to leave the car. These switches C2 and C3 are connected respectively to contact segments on the floor selector FS associated with the second and third floors, respectively.

- Assuming that the person in the car. desired to leave the car at the second floor and so notified the attendant, the attendant would press button C2 to complete the circuit energizing a contact segment '73 on floor selector Fs which circuit extends from line conductor L1 through this circuit.

the car C'will bridge contact segment 73 with acontinuous contact strip 78 to thereby supply current to the flash signal lamp FL and stop relay SR which circuit extends through contact strips '78 through conductors 79 and 58 to flash signal lamp FL and relay SR,=as previously traced for Buttons within the car, such as buttons C--2 and C-3, are now incoinmon use in connection with elevator signaling systems and may be utilized, if desired. These buttons are usually'provided with some device for holding the same in circuit-closing position when pressed, and I have illustrated such a device diagrammatically as comprising a mechanical latch 80 which, when the butt-on C is pressed, will engage a' locking bar 81 to hold the button 0-2 in circuit-closing position. A resetting coil 82 may be controlled by a reset button 83 to disengage the mechanical latch 80 from the bar 81 to restore the buttons at the completion of the trip. a

While I have illustrated thepreferred forms of my invention, it is to be understood that the foregoing description is for illustrative purposes only, and I do not desire to be limited by any of the details shown, except as defined in the appended claims.

I claim:

1. In an elevator control system having means operable in accordance with the position of the car with respect to the floors for automatically stopping the car accurately at the floor levels, attendant controlled means movable to one position to cause said car to run and-movable to another position to render said stopping means effective to stop said car at the next fioor level approached thereaftena passenger controlled sig nal system and means operable thereby to render said stopping means eifective independent of the position of saidattendant controlled means.

2. In an elevator control system an elevator car havingmeans operablein accordance with the position of said car for automatically stopping said car level with the floors served thereby, attendant controlled means on said car movable to 'a running position to start said car and movable to a stopping position to render the stopping means eiTective to stop the car at the next floor level approached thereafter, a passenger controlled call system comprising means operable by prospective passengers at a floor to register a call for service at that floor, and means operable upon the approach of said car to the fioor at which said passenger operated means is actuated for rendering the stopping means effective to stop the car independent of the position of the attendant controlled means.

3. In an elevator control system, an elevator car operable past a plurality of floor levels and having means operable in accordance with the position of the car with respect tothe floor levels for automatically maintaining the car in motion and for decelerating and stopping 'the car accurately level with the floor levels, a car switch on said car operable from a normal oiT position to a car running position to start the car, and operable to the normal position to place the control of the car under the automatic decelerating and stopping means, a passengers call system including a switch for each floor operable prior to the arrival of the car at that floor and means 5 operably responsive to the approach of the car to the floor, and means operably responsive to the combined actuation of said call system switch and said car approach means for rendering said car switch ineffective to control the car and for rendering the said decelerating and stopping means effective independent of the position of said car switch.

4. In an elevator control system for an elevator car operable past a plurality of floor levels and having means for automatically stopping said car level with said floors, control means for said elevator car, a circuittherefor, a car switch operable to a running position for supplying current to said circuit to start said car, and operable to an off position to cut off current from said circuit to thereby place the control means under the control of said stopping means, a passenger controlled call system including passenger actuated means operable to register a call for service at any of said floors, and means operably responsive to the approach of the car toa floor for which said passengers controlled means is actuated for also cutting off curent from the circuit controlled by said car switch independent of the position of said car switch.

MILTON BARE-CH. 

